1. Field of the Invention
This invention relates generally to flat-article sorting apparatus and more particularly to those of the type designed to rearrange a set of flat articles in a predetermined order and suited, for example, for use in rearranging flat mail pieces in the order required for delivery.
2. Description of the Prior Art
For mail delivery, it is necessary to arrange a large number of mail pieces in advance in the order that they are to be delivered. To perform such mail arrangement in an automatic fashion, a mail delivery sorting apparatus has already been proposed, in which sort codes placed in advance on individual mail pieces to represent the destinations thereof are read out and the mail pieces are sorted for delivery by use of the read-out sort codes. In prior art mail delivery sorting apparatus, sort codes placed on the mail pieces to be sorted for delivery are read out and the mail pieces are sorted in a set of pockets in accordance with the sort codes read out, followed by secondarily sorting or rearranging the mail pieces in each of the sort pockets in the order of delivery. In such prior art apparatus, however, different numbers of mail pieces are stored in the individual sort pockets because the numbers of mail pieces addressed to respective destinations usually differ from each other, varying day by day or season by season. On account of this, every sort pocket is required to have all the same full large capacity, involving the disadvantages such as an unduly large size of the sorting apparatus as a whole and an extremely limited rate of utilization of the sort pockets.